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Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins. Here, we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var. yunnanensis. Among them, a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides, respectively. These UDP-glycosyltransferases showed astonishing substrate promiscuity, resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds. A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments, and a mutant UGT91AH1Y187A with increased catalytic efficiency was obtained. The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes, and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects. The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.
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Objective To observe the effects of functional electrical stimulation (FES) based on a normal walking pattern on the lower extremity function of subjects early after cerebral infarction.Methods Twenty patients with cerebral infarction aged (59.7 ± 10.1) years (range 45-80) who were hospitalized and within 3 months (31.1 ± 19.3 days) after the onset were randomly assigned to an FES group (n =11) or a placebo stimulation group (n =9).All subjects in both groups received standard medical and rehabilitation treatment.In addition,the FES group received FES and the placebo group received sham-FES without current output.The daily stimulation and shamstimulation sessions lasted for 30 min,5 d/week for 3 weeks.All of the subjects in the two groups were assessed using the Fugl-Meyer assessment (FMA),postural assessment for stroke patients (PASS),the Berg balance scale (BBS),functional ambulation categories (FACs) and the modified Barthel index (MBI).Results After 3 weeks of treatment,FMA,PASS,BBS and MBI scores had all improved significantly compared with before treatment in both groups,but the FES group showed significantly better improvement.After treatment the average FAC results of both groups had improved,and there was no significant difference between the two groups.At the same time,the research revealed the expected significant correlations among the FMA,PASS,BBS and MBI results.Conclusion FES based on a normal walking pattern can improve lower extremity motor function early after cerebral infarction,improve balance,and improve ability in the activities of daily living.
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Objective To observe the effects on somatosensory evoked potentials (SEPs) of multichannel functional electrical stimulation (FES) of the legs based on a normal walking pattern,and to compare the effects with two-channel functional electrical stimulation.Methods Thirteen healthy young volunteers (6males and 7 females) were randomly assigned to receive 2 sessions of either two-channel FES for 30 minutes or four-channel FES for 15min with a 3-day interval between the two treatment sessions.The latencies and amplitudes of the N9 and P40 SEPs were recorded before and after every treatment.All the treatments were carried out on the right lower limbs.Results Thirteen healthy young volunteers (6males and 7 females) were randomly assigned to receive 2 sessions of either two-channel FES for 30 minutes or four-channel FES for 15 min with a 3-day interval between the two treatment sessions.The latencies and amplitudes of the N9 and P40 SEPs were recorded before and after every treatment.All the treatments were carried out on the right lower limbs.Conclusions The N9 latency with four-channel FES is remarkably shorter than that with two-channel FES on the legs of healthy young subjects,suggesting that multichannel functional electrical stimulation based on the normal human walking pattern can activate brain cells faster.
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Objective To compare the effects of three different training patterns of MOTOmed training on the somatosensory evoked potentials (SEPs) of healthy youths. Methods Ten healthy young volunteers received training in patterned sequences of passive movement, active movement with no resistance and active movement with resistance. Each pattern lasted for 30 minutes and SEPs were examined before and after 90 minutes of training. The amplitude and latency of N9 and P40 were recorded. Results All three training patterns heightened SEP amplitude and lengthened SEP latency, but active training had the most obvious effect on amplitude. The rates of change of am-plitude after each training pattern had significant differences, which was most obvious after training the resistance training pattern. Conclusions MOTOmed motor training can excite the cerebral cortex and up-regulate SEP ampli-tude. Active movement with resistance is the most effective among the three patterns tested.
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Objective To analyze the clinical and electrophysiological features of one geneology with limbgirdle muscular dystrophy(LGMD). Methods Twenty-seven members of one family with limb-girdle muscular dystrophy(LGMD)were investigated.Fourteen of them were examined with electromyography(EMG)and their motor conduction velocities(MCV)and sensory conduction velocities(SCV)were measured.Among them,10 had no clinical manifestations,while 4 demonstrated symptoms and signs of LGMD. Results Three of the 4 patients had suffered from LGMD when young.They demonstrated the typical clinical features,including the progressive muscle weakness in the upper and lower extremities,positive Gower signs,duck gait,muscle atrophy distributed tO the proximal extremity,and no gastrocnemius hypertrophy.One subject presented atypical characteristics.The MCVs and SCVs of the 4 patients were normal,but neuropathic manifestations were found in the EMGS of 3 of them.and mixed neuropathic and myopathic manifestations were found in the EMG of the other.Conclusion LGMD patients in the same family can vary in their clinical characteristics.The longer the duration,the more severe the clinical features.Electrophysiological examination can reveal normal MCV and SCV but abnormal elctromyography.